JavaScript Objects and Prototypes

Create Objects

Using function

Create Objects without duplication code: use functions

Using constructors

To indicate a function is a constructor:

append new keyword in front of the function name when executing it

Call

Property of function object
foo.call() = foo()
Call can bind different objects and can execute functions

__proto__

Copy of prototype object

If some property is not in the object itself, it then looks it in the prototype. If it finds it returns the value of that property
All the new object instances of function point to same prototype object
prototype.constructor: property that points to function

GitHub repo: https://github.com/kaosadi17/JavaScript/blob/master/objects%26prototypes.js

Comments

Object Oriented Programming (OOP)

Object Object is an entity that has state and behavior Class Collection of objects is known as class. There are four main types of OOP concepts Inheritance Object acquire all the properties and behavior of parent object Improve code re-usability Polymorphism One task is performed by different ways Use method overload and override Abstraction Hiding internal details and showing functionality Use abstract class and interfaces Encapsulation Binding code and data into a single unit

Java-8

Java 8 New Features There are several new features added in Java 8 version. Some of the important new features are: Define methods inside the interface For each method Lambda Expression Stream API DateTime API 1) Define methods (default, static) inside the Interface After you published your interface, you can't change it by adding some abstract methods. But if you want to add methods you can define those methods inside the interface. Therefore Java 8 support default and static methods inside the interface. In Java 7 version interface only have abstract methods (no method implementation) and an abstract class can have both abstract and non-abstract methods. In Java 8 version you can add method implementation in the interface, but you have to declare that method as default method. ex: default void show(){............} To avoid diamond problem you have to override the method in implementation class if two interfaces have same default method ...

Model-View-Controller (MVC)

MVC(Model-View-Controller) is a software design pattern.It divided your applications into three components Model: Contain business rules and application Data View: Presentation layer (user interface) Controller: Handles the communication between view and model Objectives of MVC Promote code usability Implement separation of concerns Separate user interface and software logic Web Frameworks That Use MVC There are several web frameworks that use MVC design pattern. Ruby On Rails (Ruby) Angular (JS) Django (Python) Express (JS) Flask (Python) Codeigniter (PHP) Simple UseCase for MVC In this use case scenario, Browser sends information that needs to create Employee Object, and Controller save that information in Model and Update the Employee View. Following Image shows the class diagram for above Scenario. Implementation: https://github.com/kaosadi17/MVC

MyTech

Search This Blog